The present invention relates to methods of producing tension within sheets of flexible materials which are supported by structural members of some sort. The present invention also relates to methods of absorbing impact loading upon tensioned sheets of flexible materials.
Fabric materials have long been used in conjunction with framework elements to provide temporary shelters of a utilitarian type. Such structures suffer to a degree from unsightly appearance due to sagging and wrinkled walls and from flapping caused by insufficiently tensioned panels. In erecting frame supported fabric structures of conventional construction, each panel which extends between a pair of spaced structural support points must be tensioned as it is put into place. In order for the installed panel to be reasonably taut, the fabric is secured to the support points on one edge of the panel and the panel is stretched toward the support points at the opposite edge of the panel. Tensioning of the panel during its installation is frequently an extremely difficult and awkward maneuver. In large structures, for example, where a panel is stretched between a pair of arches, heavy mechanical equipment such as cranes must be used to install the panel in a reasonably tensioned state.
In actual practice, it is sufficiently difficult to erect frame supported fabric structures which are neat in appearance, that such structures are seldom used where aesthetic considerations are involved. Another problem with such structures is that when a highly tensioned state is achieved in the fabric to render the structure pleasing to the eye, they are highly vulnerable to the impact forces generated by wind gusts. The highly tensioned fabric panels are not able to deflect and absorb the impact loads and therefore these loads are transmitted directly to the supporting points causing damage to the frame or the ground anchors.